I am trying to transfer .001 ETH from MyEtherWallet.com to an exchange, and while I realize I may not have enough to transfer, it mentions I need "GAS".

I tried reading and understanding the process, but it is still confusing.

I get the Error Message: Transaction gas is too low. There is not enough gas to cover minimal cost of the transaction (minimal: 21000, got:1). Try increasing supplied gas.


I type 21000, but I still get an error message.

How do I get to understanding GAS

Do cold wallets have to use GAS?  ie) Trezor/Nano?